Pea weevil, is the name of the insect, distributed in most provinces and regions of China, especially in Jiangsu, Anhui, Shandong, Shaanxi and other provinces. Harm peas, lentils, etc.; larvae infested with bean Ying, feeding on bean grains, affecting the yield, and the victimized bean Ying smells bad and is inedible.

Catalog

Morphological Characteristics

Biological Characteristics and the Law of Occurrence and Dissipation

Reasons for Introduction and Spread and Harm

Control Methods

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Edit this paragraphMorphological Characteristics

Adult

Body ellipsoid, 4-5.5mm long. The epidermis is black, with only the basal 4-5 segments of the antennae, and the upper lip, forefoot and midfoot tibial and tarsal segments reddish brown. The head is densely covered with small incised dots, covered with light brown hairs; the compound eyes are "U"-shaped with narrow and deep depressions. Prothoracic dorsal plate transversely broad, densely punctate, with mixed brown, pale brown and pale white hairs, posterior margin centrally with triangular patch of white hairs; lateral margin centrally slightly anteriorly with a lateral tooth, the tip of which points posteriorly, and the lateral margin partly concave and obliquely oblique behind the tooth. Peltae subangular, posterior margin centrally concave, bearing pale white hairs. Scutellar wings covered with incised dots; lateral margins subparallel, about one times as long as shoulder width, scutellum prominent; each scutellar wing with 2-3 small white hair patches on basal half, often with a band of white oblique hairs on telescopic half, oblique hair bands on both wings forming a "figure of eight" shape. The buttock plate is covered with dark brown hairs, and there is an ovoid black spot on each side of the proximal part. There is a small, pointed spine at the end of the tibial segment of the midfoot in females, but not in males. The terminal anterior tooth on the ventral surface of the leg segment of the hind foot is large and pointed.

Specimens of the pea weevil from different countries or regions of the world show considerable variation in the color of the antennae, legs, and indumentum. For example, specimens from Central Asia, the black spot on the buttock plate is not obvious, and the antennae of males are all yellow, while the basal five segments of the antennae of females are yellow as well as the terminal segments, the tibial segments of the prolegs and the mesopods; specimens from the former Asian and South Asian regions, some individuals are covered with light gray hairs on the dorsal surface of all the hairs, with no obvious dark hair patches and transverse bands.

Eggs

Oval, yellowish, ca. 0.8 mm long. bearing 2 filaments ca. 0.5 mm long at the thinner end.

Larvae

Old mature larvae are 4-5mm long and 2-2.5mm wide. white in color, with a cauliflower shaped body curved ventrally. The head is rounded, with 3 setae in the frontal region; 1 seta on each side of the labial base; the upper lip is ovoid-transverse and broad, ossified at the base, bearing numerous small spines on the anterior margin, 3 long setae near the anterior margin, and 2 setae at the base; the anterior margin of the upper inner lip is armed with numerous small spines and bears 4 ciliated setae, and there are four short, thick setae in the middle. Antennae 2-segmented, only terminal segment ossified, antennal setae beyond tip of antennal terminal papillae; maxillae triangular; mandibles bearing setae anteriorly and centrally on stem segments, mandibular whiskers conical, 1-segmented, apically bearing 1 set of secondary papillae; posterior chin slightly "C"-shaped, membranous, indistinctly demarcated from anterior chin, bearing 1 pair of anterolateral and 1 pair of median setae; Anterior chin with 1 long peltate segment, bilobed anteriorly, broadly rounded posteriorly, with 1 seta on each side of proximal anterior sinus, and 1 pair of setae in middle of labial tongue. Number of annuli on anterior, middle, and posterior thorax 2, 2, and 3, respectively. foot composed of 3 segments. Abdominal segments 1-8 with 2 annuli per segment, segment 9-10 with 1 annulus per segment. Valves ring-shaped.

Pupa

Oval, body length about 5.5-6mm, yellowish. Prothoracic dorsal plate and sheath wings smooth and unwrinkled.

Edit Biological Characteristics and the Law of Occurrence and Elimination

1 generation per year. The period of occurrence in various places, from north to south gradually earlier. Peas began to flower, adults began to come out; peas bloom, adults are also prevalent; peas mature, adults extinct. The insect mainly overwinters as an adult inside the pea grains, in warehouses, wall cracks, packages, and under the eaves, wooden posts, fences, and tree bark in the field, but most of them are inside the pea grains. A few individuals were also found to overwinter as larvae or pupae. The egg stage lasts 6-7 days in Jinnan, 8-9 days in Shaanxi Province, 7-10 days in Yutai, Shandong Province, and 5-8 days in Nanchang, Jiangxi Province (up to 18 days). Larval stage 20-34 days, 35-42 days in Shaanxi Province, 35-60 days in Luotian, Hubei Province, 32-50 days in Nanchang. *** Calendar 4 instars. The pupal stage is 6-14 days in Jinnan, 9-15 days in Yutai, 8-14 days in Luotian, and generally 8-9 days in Nanchang. Adults live 25-40 days after stinging, and their life span (including the overwintering period) reaches 9-11 months. The egg-laying period is 8-10 days.

Adults lay eggs on pods, mostly on young pods 7 days after the corolla falls off, occasionally on the calyx; the eggs are mainly laid in the middle of the plant, followed by the lower part, and less on the upper part. Eggs are laid singly, and sometimes two grains overlap each other. The larvae and pupae are inside the bean grains, with one head per grain. Adults are found on flower buds and young pods, and in the morning and evening they inhabit the stamens or young leaves. Regarding the fecundity of females, the amount of eggs laid by females reported by different authors varies widely, from less than 100 to an average of more than 400.

Editorial paragraph introduction spread causes and harm

Now except Australia, has been all over the world. 1950s in China began to harm, in 1957 Hebei Province survey, in addition to Zhangjiakou, the province are occurring. 1965 introduced into the Xinjiang Tacheng and Yili area, quarantine personnel, although timely detection, but no one to catch, resulting in the rapid spread of the fall of 1958 a large number of In the fall of 1958, when a large number of seeds were transferred into the disaster relief, the broad bean weevil and pea weevil were transferred from Hunan and Hubei to central and southern Guangxi, resulting in the Guilin area to become a serious occurrence of these two species. 90 years since the central Gansu area has been serious. It is mainly spread through the transportation of infested seeds. Harming peas, kidney beans, wild peas, cassia, goldfinch, sallow beans and other plants.