Biology and physical ecology ofApanteles subandinusBlanchard (Hymenoptera: Braconidae), with notes on temperature responses ofApanteles scutellarisMuesebeck and its host, the potato tuberworm

Abstract

Laboratory investigations were conducted on the biology of Apanteles subandinus Blanchard and the effect of temperature and relative humidity on its bionomics. Temperature responses of this parasite were compared with those of Apanteles scutellaris Muesebeck and their common host, the potato tuberworm, Phthorimaea operculella (Zeller). Responses of the parasites and their host to physical factors were evaluated by using the intrinsic rate of natural increase (r) as a bioc1imatic index. At 80°F and 50 per cent relative humidity (R.H.) the mean duration of the life cycle of A. subandinus from egg to adult was 15 days; egg, 1 day; first instar, 4.5 days; second instar, 2.5 days; third instar, 2 days; prepupa, 0.5 days; and pupa, 4.5 days. The parasite egg is deposited at random in the body cavity of the host larva where the parasite larva develops. There are three Instars, the first being mandibulate-caudate and the other two' hymenopteriform. The mature larva emerges from the host, killing it in the process, and spins a silverwhite cocoon. There is essentially no preoviposition period in A. subandinus and the parasite is an arrhenotokous species, the virgin female producing only male progency. Between 60 and 90°F, speed of development was directly related to temperature. A constant temperature of 95°F prevented development of the parasite beyond the first insrar. Longevity and reproductive periods were inversely related to temperature, longevity following the pattern of the curve of physiological longevity. Production of progeny was maximum at 80°F. As determined by calculations of the intrinsic rate of natural increase, A. subandinus persisted and increased in numbers between 60 and 90°F. Optimal temperature for the parasite was 85°F. Relative humidity did not affect development. At 80 and 85°F, maximum progeny production occurred at 50 per cent R.H.

Bionomics of the potato tuber moth,Phthorimaea operculella(Lepidoptera: Gelechiidae), at Pukekohe

“…Summer build-up of the parasite population did not begin until 2-3 months after the explosion of its host (see Fig. 10); however, because of a relatively faster rate of increase (Cardona & Oatman 1975), maximum parasitism coincided with the tuber moth population peak. The sustained high winter level of parasitism seen in Fig.…”

“…Although the life cycle of the moth has been studied in many countries (Langford & Cory 1932, Langford 1934, Attia & Mattar 1939, Mukherjee 1949, Lall 1949, Bartoloni 1951, Koizumi 1955, El Sherif 1961, Stanev & Kaitazov 1962, Doreste & Nieves 1968, Yathom 1968, Broodryk 1970, Salama et al 1973, AI-Ali et aI. 1975, Cardona & Oatman 1975, few studies have been made of infestation behaviour (Bald & Helson 1944, Meisner et aI. 1974, Traynier 1975 or of survival patterns within the life cycle.…”

“…The larval parasite Apanteles subandinus is considered to be one of the more promising parasites for controlling P. aperculella (Rao & 1968, CSIRO 1969, Cardona & Oatman 1975 Parasitism was monitored from February to October 1973. The population was sampled from exposed tubers left on the ground after a spring potato crop on the DSIR substation.…”

“…Newly hatched parasites and tuber moth adults were removed and counted daily. Percent parasitism at each sample date was calculated from the number of parasites emerged divided by the total emergence of moths plus parasites (A. subandinus is a primary solitary larval endoparasite, and the production of one parasite therefore costs one tuber moth life ;Cardona & Oatman 1975).…”

The Potato Tuberworm: A Literature Review of Its Biology, Ecology, and Control

“…The biology of P. operculella has been studied extensively all over the world (Langford 1932;Langford and Cory 1932;Attia and Mattar 1939;Lall 1949;Mukherjee 1949;Bartoloni 1951;Manickavasagar 1953;Koizumi 1955;El-Sherif 1961;Stanev and Kaitazov 1962;Doreste and Nieves 1968;Yathom 1968;Broodryk 1970Broodryk , 1971Santorini 1971;Ono et al 1972;Salama et al 1972;Ono and Saito 1973;Al-Ali et al 1975;Cardona and Oatman 1975;Fenemore 1977;Gubbaiah and Thontadarya 1977;Haines 1977;Fenemore 1978;Brits 1979;Fenemore 1979;Choe et al 1980;Shelton and Wyman 1980;Chauhan and Verma 1985;Briese 1986;Chauhan and Verma 1991;Trivedi and Rajagopal 1992;Rondon et al 2007;Dŏgramaci et al 2008). Other P. operculella work includes detailed morphological studies carried out by Mukherjee (1949) and continued by Bartoloni (1951) and Brits (1979); and mass-rearing methods (Finney et al 1944;Finney 1947;Platner and Oatman 1968;…”