Biology of the Mealybug,Phenacoccus solenopsison Cotton in the Laboratory

Abstract

Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) has been the current topic of research for insect taxonomists and applied entomologists in India due to its invasiveness, rapid spread, morphological and biological variations and the need for establishing an effective control strategy. The biology of the mealybug P. solenopsis was studied on cotton under laboratory conditions between August and October of 2009 with mean temperature and relative humidity of 23.3–30.2°C and 40.5–92.5% RH, respectively, in central India. Neonate crawlers that emerged from a field population were collected and constituted the study population. The developmental period from immature crawler to adult stage was greater for males (18.7 ± 0.9 days) compared to females (13.2 ± 1.8 days), probably due to the additional molt to the pupal stage in males. Survival of second instars was lower (45.5%) than first and third instars (71.4%). Females showed dynamic patterns of fecundity with the number of crawlers produced per female ranging between 128 and 812, with a mean of 344 ± 82. The reproductive period lasted 30.2 ± 8.2 days. Parthenogenesis with ovoviviparity (96.5%) was dominant over the oviparous (3.5%) mode of reproduction. Adult females lived 42.4 ± 5.7 days. Males accounted for less than 5% of the population, and lived 1.5 ± 0.1 days. The life history parameters of P. solenopsis adult females are discussed relative to the appearance of symptoms on the cotton crop, and the importance of making management interventions during the effective reproductive period of the insect.

Biology of the Mealybug, Phenacoccus solenopsis Tinsley Infesting Bt Cotton

“…Similar observations reported by Nikam et al, (2010) and Vennila et al, (2010). Newly emerged crawlers were light yellow in colour (Plate 2), light red eyes, three pairs of legs and a pair of seven segmented filiform antennae as observed under microscope.…”

“…The present finding is in concurrence with the results of Nikam et al, (2010) and Vennila et al, (2010) who observed male cocoon after third molt and reported that sex differentiation could be difficult in third instar and in disagreement with the report of Hodgson et al, (2008) who observed the male cocoon after second moult.…”

“…Duration of male cocoon was varied from 4 to 7 days with an average of 5.35 ± 1.18 days (Table 1). Nikam et al, (2010) and Vennila et al, (2010) reported that male nymph passed through the fourth instar and the duration of which varied from 6 to 7 (av. 6.40 ± 0.48) days and 5 to 7 (av.…”

“…According to Akintola and Ande (2008) longevity of female was 37 days. Vennila et al, (2010) observed it to be ranged from 1 to 2 (av. 1.5 ± 0.1) days in males and 36 to 51 (av.…”

Do organic silicon and imidacloprid synergistically induce toxicity to the new invasive mealybug Phenacoccus solenopsis Tinsley on Portulaca grandiflora plants?

“…In a bad infestation, their honeydew induces the development of sooty mold fungus (Saeed et al, 2007). This species has been recognized as an aggressively invasive species of agricultural and ornamental plants in China. P. solenopsis in the fields is difficult to manage (Ram and Saini, 2010;Vennila et al, 2010;Huang J et al, 2012;Zhou et al, 2012) for the following reasons: 1) this species possesses a waxy coating that protects it from insecticides and natural mortality factors, 2) P. solenopsis can also hide in soil cracks and crevices, 3) P. solenopsis exhibits a high reproductive rate and produces serious overlapping generations, and 4) the higher foraging tempo of ants provides additional effective protection for P. solenopsis. P. solenopsis cannot be controlled effectively; the losses in cotton yield in 2008 or 2009 were 1.4 × 10 6 t in China, 1.12 × 10 6 t in India, and 0.48 × 10 6 t in Pakistan (Wang et al, 2010).…”