General Entomology Plant Protection Profession - College Part 1 - Dong Thap Community College

This is also one of the largest families of the Lepidoptera, including many important plant pests. The body is small, gray or dark brown and often has dark bands present on the wings. The forewings are usually rectangular. At rest, the two wings fold into a roof shape on the back. The 1A vein of the forewing is only a short segment on the outer edge of the wing. The Cu2 vein of the forewing originates from 1/3 to 3/4 of the lower edge of the mid-wing chamber. The Sc+R1 vein of the hindwing is separate, not connected to the other veins.

Larvae have long, small bodies and sparse hairs. Their toenails (abdomens) are often arranged in a closed circle. Larvae have the habit of rolling leaves, weaving leaves or boring into young shoots, young stems and fruits to cause damage. Common pests include: tea leaf roller ( Homona coffearia ), leaf roller ( Cacoecia eucroca ), Dudua aprobola leaf rollers of mango, lychee, and bamboo shoots...

d) Geometridae family

With about 1200 species discovered in the United States and Canada. Adults are mostly small, thin, long body, wings are often wide and on the wings often have small lines. Males and females often have different colors, in some species, females have degenerated wings or no wings, when perched, 2 wings spread horizontally. In the forewing, the R vein divides into many branches. But all veins R1, R2, R3, R4, R5 meet at a point inside the wing. The longitudinal vein Sc of the hindwing is very curved at the base and often has a very hard transverse vein attached to the shoulder base. Adults are nocturnal and are often attracted to light. Larvae are inchworms, have only one pair of abdominal legs at the 6th segment and one pair of rump legs at the 4th segment

10. When crawling, the thoracic legs are firmly attached and the abdomen is curved. When standing still, the thoracic legs and rump are firmly attached and the front part of the body hangs outside like a small tree branch. The larvae mainly feed on leaves.

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In the Mekong Delta, there are often types of inchworms that damage cotton, mango leaves, longan, and rambutan such as Thalassodes falsaria, Comibaena spp., and Hyposidra talaca.

e) Family Sphingidae

Medium to large size, rough body, 2 ends slightly pointed like a diamond, some species when stretching the wings, the body width reaches 160 mm. The antennae are often slightly swollen in the middle or at the end of the antennae. The forewings are long and narrow, the hindwings are small. Between the longitudinal veins Sc + R1 and R5 of the hindwing there is a transverse vein. The proboscis of many species is very developed, sometimes as long as the body length, the ability to fly is very large and fast, some species are active during the day, but most are active at dusk.

Larvae are large, each abdominal segment is divided into 6-8 narrow rings, the back of the 8th abdominal segment has a large spine so it is also called "horn caterpillar". Larvae bite and destroy leaves.

Very strong plant, especially on potatoes, tomatoes, tobacco.

Common species: Sweet potato leafhopper ( Theretra oldenlandia Fabr)

f) Lymantriidae

Most are medium in size, similar to the family Noctuidae, but unlike Noctuidae this group lacks simple eyes and has a "basal chamber" (basal areole) at the base of the hindwing, in most species the thorax and abdomen are covered with dense hairs, in many species in females there is a distinct tuft of hairs towards the end of the abdomen.

Larvae have many hairs or tufts of hairs, with open claws (abdomen) arranged in rings, and mainly bite and destroy leaves. In the Mekong Delta, many pests on fruit trees belonging to the genera Lymantria, Orgyia and Euproctis have been recorded.

g) Family Plutellidae

Small body, usually ash gray, long narrow wings, pointed hind wings, very long hairs on the edge of the wings. R5 vein of the forewing can extend to the outer edge, R2 and R3 veins of the hindwing share the same vein. The antennae are usually extended forward when perched. Larvae are mostly green, slightly tapered at both ends, pupating in a thin, loose cocoon. Including important pests on cabbage and other plants of the family Crucifera, larvae can eat through leaves and pupate in a thin cocoon on the leaf.

Common species: cabbage looper Plutella xylostrella

h) Gelechidae family

Including many very common insects, relatively small in size. The lower lip antennae are long and curved upwards, the third segment is long and pointed. The R4 and R5 veins on the forewings share a common segment at the base and the 2A vein branches at the base. The damaging habits vary by species, some species bore into the leaves, some species form galls, some species roll the leaves.

Important pests are the rice weevil Sitotroga cerealella , the pink cotton worm Pectinophora gossypiella ., and the moth Anarsia sp. which damages mango, longan, and litchi.

i) Cossidae

Adults are medium sized, with hairy bodies and wings that are usually ash-colored or white with black spots. Wing veins are quite primitive. The middle vein is at the base.

(M) of the wing remains and branches in the middle chamber, forming a small chamber (both forewing and hindwing). The forewing has Cu2 vessels, the hindwing has 3 A vessels. The wing hook is sometimes very short, sometimes very developed, the female has up to 9 hooks, the hind leg segment has a short spur. The antennae are double-toothed. Damage is mainly caused by boring into the tree trunk, common species include Zeuzera coffeae and Cossus spp.

j) Family Psychidae

Male adults are usually small, with developed wings, female adults are wingless, legless, and live all their lives in a woven bag made of leaves and plant residues, so they are also called bagworms. Mating and egg laying are both in that bag or pouch. The forewings of the male also have the main stem of the M vein in the middle chamber, so this chamber is divided into two small chambers. Veins 1A and 2A merge together into one. Male adults usually have a degenerated proboscis, a double-toothed antennae. Larvae have strong thoracic legs, degenerated abdominal legs. Larvae also give birth to

k) Leaf miner (Gracillariidae)

Including species ranging in size from small to very small, the wings are pointed at the tip like a spear (lancet), the costal veins are often slightly curved, and are raised at the base of the wings. In the resting state, the front part of the adult body is often raised forward, and the wing tips often touch the surface where the insect is resting. Larvae often cause damage by eating through the leaves, creating long, winding tunnels between the upper and lower epidermis of the leaves.

On oranges, the leaf miner ( Phyllocnistis citrella ) is often found to cause damage. The larvae usually start to bore into the leaf, near the tip of the leaf and bore from top to bottom. They pupate in a silk cocoon at the end of the tunnel, located on the lower edge of the leaf.

l) Bombycidae family

Medium body size. Head degenerate, lower lip antennae small or absent, head antennae double-toothed. Longitudinal veins R1, R2, R3 of the forewings are separate and originate from the R4+5 veins, between the longitudinal veins Sc+R1 and R5 of the hindwings towards the base of the wing there are transverse veins. Many species have the habit of spinning silk to weave cocoons, the common species is the mulberry silkworm ( Bombyx mori L.). Adults are often milky white with many faint, horizontal, brown stripes present on the forewings. The body width when the wings are stretched can reach 50 cm, the body is heavy, has many hairs. Adults do not eat, rarely fly and only live a few days. Each female can lay 300 - 400 eggs. To get the silk, the pupa is usually killed before emergence. Each cocoon can be stretched into a long thread, up to 914 meters long.

m) Hesperiidae family

Most have small, rough bodies, large heads, two antennal sockets that are often far apart, and the end of the antennae is hook-shaped. This family is different from most other butterflies because all five R veins of the forewings usually originate from the middle chamber of the wing. Larvae often have soft bodies, large heads, and small necks, often living in leaf rolls and causing damage there.

The common species in Vietnam is the banana leaf roller Erionota thrax.

n) Family Papilionidae

Including species with very large sizes, some species, the body width when the wings are spread can reach 255 mm, the body has many beautiful colors, males and females have different colors in some species. The R vein on the forewings consists of 5 branches. And the hindwings often have a long tail. The larvae often have a smooth body or a convex shape, when agitated, you can observe on the front edge of the forewings two odorous glands, Y-shaped, protruding forward. The abdominal claws have two or three forms arranged in a single, vertical row. Most eat leaves of citrus trees of the Loraceae family.

o) Nymphalidae Butterfly Family

Includes many species belonging to groups that were previously considered to belong to different families: Satyridae, Danaidae, Brassolidae, Amalthusiidae, Morphidae, Acraeidae, Heliconiidae and Ithomiidae. Most species are medium to large in size, brown or reddish brown, red. The forelegs are poorly developed, especially in males, the metatarsals are often fused together. Most are fast flyers.

The larvae are of various forms, some with horns on the head as in the Satyrinae, some with filaments as in the Danainae, and some with sharp spines as in the Nymphlinae. The pupae are also different, but all groups have pupae attached to the plant by means of filaments at the end of the abdomen. Many subfamilies have specialized feeding habits, such as the Satyrinae which mainly damage monocotyledons, and the Dainainae which mainly damage the herbaceous groups Asclepiadasceae, Moraceae and Apocynaceae.

p) Pieridae

Usually consists of butterflies that are white, yellow or orange mixed with brown spots and streaks, mostly of medium size. The R-vein usually has only 3 - 4 branches, rarely 5 branches. The forelegs are developed, with two claws. The pupae are usually long, narrow and are often attached to plants by silk threads at the end of the abdomen and by a silk thread tied around the middle of the body to the plant. Many species of this family are capable of migrating in flocks. The larvae are usually green, long with short hairs, mainly damaging plants of the Cruciferous family such as white butterflies Pieris spp.

4.5. Diptera

Consists mainly of flies and mosquitoes. This is one of the largest orders of the insect class, including a number of species that are very rich not only in the number of individuals but also in the number of species, present almost everywhere. Basic characteristics: there is only one pair of wings, the forewings, while the hindwings are very small and club-shaped.

Most are small in size, have soft, weak bodies and a few species are very large in size.

Although small, many species in this order play an important economic role. The mouth is generally of the sucking type, but there is great variation in the structure of the mouth between families. Many species have a sucking mouth, others have a licking or licking mouth, and a few have a reduced, inactive mouth.

Complete metamorphosis, larvae are called maggots (for flies) or wriggling (for mosquitoes). Mosquito larvae have developed heads, chewing mouths. Fly larvae have very small degenerated heads, no legs, mouths consisting of only one or two hooks, moving up and down vertically. In some species of flies, the head of the larvae is hardened, more or less elastic.

Diptera larvae can live in many different environmental conditions, a large number of species live in water. The feeding habits of larvae can include 4 types: herbivorous, humus-eating, fecal-eating, predatory and parasitic. For the herbivorous group, larvae cause damage mainly by boring into and living in plant tissue such as leaf borers, stem borers and root borers. The predatory group mainly includes types that attack small, soft-bodied insects such as aphids, mealybugs, etc.

The parasitic group includes some of the most important species of the family Tachinidae, mainly parasitic on larvae and pupae of the order Lepidoptera. Besides the group of plant parasites, the group of animal parasites is also very rich, including species that parasitize the bodies of livestock, not to mention many species that are vectors of many dangerous diseases for humans such as flies and mosquitoes.

* SOME IMPORTANT FAMILIES

a) Family Cecidomyidae

Also known as butterfly mosquitoes. These are very small, thin mosquitoes with long thoracic legs, long beaded antennae, surrounded by hair, degenerated wing veins, wing veins with only 2-3 lines, no transverse veins.

Most larvae are brightly colored (orange, pink or yellow). Most larvae live on plants, mainly in the galls of leaves, branches and fruits and many other parts of the plant. Galls can contain only one larva or many larvae depending on the species. A few species are predatory, attacking aphids, aphids and other small insects. In addition, there are also a few species in this family that feed on decaying organic matter or fungi.

Common species: Rice-borne midge ( Pachydiplosis oryzae )

WoodMason) and mosquitoes that damage mango leaves.

b) Chironomidae family

Present almost everywhere. Most are small, thin, and very similar to

Common house mosquitoes but the pink mosquito has no scales on its wings and no sucking proboscis and the male has a well-developed pinnate antennae. The larvae live in water, in ponds or slow-moving water. Some species are red due to the presence of hemoglobin in their blood.

Common species: pink mosquito that damages water fern ( Chironomus sp.).

c) Fruit fly family (Trypetidae)

These are medium sized flies, with many dark spots or markings on the wings. Usually brown, yellow, black or mixed. The Sc veins curve towards the leading edge of the wings. The ovipositor of the female is distinct and divided into 3 segments.

Habits: live in fruits, branches, leaves or plant tissues, forming tumors. Common species: fruit fly ( Bactrocera dorsalis ).

d) Family Agromyzidae

Small (1.5-4.0 mm), usually black or yellow. Oral hairs, head antennae glabrous or bristle-like but not pinnate. Femoral segments bristle-like. Wings inner or streaked. Sc vein undeveloped or separated from R1 vein only at base. Larva tubular, anterior segment pointed, posterior segment blunt.

Larvae cause damage by boring into leaves in zigzag patterns. Some species, after boring into leaves, continue to bore through the leaf stalk, down the stem and cause damage to the stem, such as stem borers on soybeans.

Common species: vegetable leaf miner Liriomyza trifolii

e) Family of parasitic flies (Tachinidae)

This is the second largest family of Diptera, with over 1,300 species recorded in North America alone. This group of flies is found everywhere. This is an important family in agriculture because most of the insects in this family are parasitic on other insects.

Adult flies lay eggs to parasitize the host, and the larvae can enter the host's body through the anus or genitals. Some species lay eggs on leaves, and when the host eats leaves containing fly eggs, the flies will develop in the host's body. Most parasitize larvae and pupae of the order Lepidoptera, but Tachinidae also parasitize Coleoptera, Dermaptera, Diptera, and Hemiptera.

Common species: Tachina sp.

f) Family Asilidae

This family includes many very common species, present in many places. Adults are predatory, specializing in attacking many other insects such as bees, dragonflies, grasshoppers and many others to survive.

These insects usually have long bodies, medium to large in size, and are hairy. Large compound eyes, with 3 simple eyes. Hard sucking mouthparts. Large thorax, long, strong legs. Very long R1 vein. Larvae live in soil or wood, eating meat or rotting humus. Larvae have round, tubular bodies, pointed heads, dark color, and breathing holes at both ends of the body.

Common species: Tachina sp.

g) Syrphidae family

Including many species, in North America alone, about 950 species have been recorded. Preliminary survey results have shown that there are over 40 different species present in the Mekong Delta. This is a family with many very common species, present almost everywhere. Adults are often found on flowers. Including many different forms but almost all can be identified by the presence of spv pseudoveins on the forewings (between the R and M veins). Most are brightly colored and have a bee-like shape.

The living habits of larvae are very complex:

- Many species belong to the predatory group, specializing in attacking aphids.

- Some species live in the nests of social insects such as ants, termites or bees.

- A few other species attack plants or feed on decaying organic matter or animal feces.

Common species: Syrphus sp.

h) Ephydridae family

Including many species of very small size, mostly dark in color, adults are often present in wet areas. Most insects live in water. Some species are capable of causing damage to crops such as Hydrellia sasakii, Hydrellia philppia and Hydrellia griseola which damage rice.

i) Family Muscidae

There are many species and they are present everywhere. Many species are pathogens for humans such as Musca domestica or are harmful to livestock such as Musca autumnalis . Some species are harmful to agriculture such as Altherigona species that damage rice.

4.6 Thysanoptera

Including species with long, slender and small bodies, from 0.5 to 5 mm long (some tropical species can be up to 13 mm long). Winged or wingless, when fully developed, the wings are usually narrow, long, with very few or no wing veins, covered with many long hairs. The mouth is of the type of sucking file mouth. The upper jaw is asymmetrically degenerated, located on the ventral surface of the head, with 3 stingers. The head antennae are short, with 4-9 segments. The feet have one or two segments. With one or two claws, with a convex bladder at the end.

In some species, the ovipositor is developed, in others, the end of the abdomen is elongated into a tube, without ovipositor. The metamorphosis of Bù lêch is intermediate between simple and complex metamorphosis. The first and second instar larvae are wingless. In the suborder Terebrantia, the third and fourth instar larvae (in Franklinothrips only the third instar) are immobile, do not feed and have wings, the third instar larvae are called pre-pupa and the fourth instar is called pupa. Pupae are sometimes enclosed in cocoons.

In the suborder Tubulifera, the third and fourth instar larvae are pre-nymphs (third instars are wingless) and the fifth instar larvae are pupae. The stages after the fifth instar are adults. This type of metamorphosis is similar to simple metamorphosis because some instars have wings (except Franklinothrips ). In addition, this type of metamorphosis is similar to complete metamorphosis because some instars are wingless or develop only internally and have an immobile (pupal) stage before the adult stage. The shape of the females and males is very similar, but the males are usually smaller.

Many species reproduce asexually (parthenogenesis), these species often use ovipositors to lay eggs in plant tissue, species without ovipositors lay eggs in crevices or under the bark. There are often several generations per year. Adults and larvae have similar living habits. Most are important pests on plants, attacking flowers, leaves, fruits, and branches. These parts when damaged by the weevils often have discolored spots or become rough, twisted, and shriveled. Weevils attack many types of plants.

Some species transmit plant diseases, such as the tobacco thrips ( Thrips tabaci ), which transmits viruses. Others cause wounds that become gateways for bacteria and fungi to infect plants. Some species also cause tumors. A few species live on fungal spores or attack other small insects.

General Entomology Plant Protection Profession - College Part 1 - Dong Thap Community College - 11

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