Advances in rearing ofLixophaga diatraeae [Dipt.: Tachinidae]

Abstract

Larvae of Diatraea saccharalis (F) were reared on artificial diet in 30-ml cups (1-3 larvae/cup). Adults of the larviparous tachinid parasite, Lixophaga diatraeae (TOWNSEND), were removed from emergence and holding cages with a modified vacuum sweeper. Maggots were extracted from I0 to 14-day-old female flies, that had been disinfected with 1% NaOC1 by one of two methods. In method 1, fly uteri were removed and placed in a 10-ml vial containing a 0.15 ~o agar-water solution with 3-4 glass beads; rapid vibration of the vial ruptured the uteri and distributed the maggots in the agar solution. In method 2, whole flies were blended with 50-ml water in a blender, and maggots were separated from fly particles by screening; then they were suspended in the agar solution. A procedure was devised for determining the number of maggots obtained by each method. The maggot-agar solution was injected into cups containing host larvae and maggots sought out and parasitized the host larvae; however, the percentage producing puparia generally decreased with increases of host larva and/or maggot density. Puparia were harvested from cups by hand and washed in 1 ~o NaOC1 to disinfect and destroy host larval webbing. KNIPL1NG (1972) demonstrated theoretically that the tachinid parasite, Lixophaga diatraeae (TowNSEND), might be used in timed releases to suppress populations of Diatraea saccharalis (F.) in the field. Thus, a rearing program to produce sufficient flies to evaluate this concept was initiated.BENNETT (1969) reviewed the biology, ecology, and laboratory rearing methods for L. diatraeae. Generally, flies were held in cages for emergence, mating, and holding until maggot extraction (L. diatraeae is larviparous, and maggots are physically removed from the fly). Uteri were dissected from flies and placed in a water droplet; as maggots exited from egg shells (hatched), 1-3 were placed via a fine brush on each host larva. Food and water were supplied to the flies daily. These methods were too time consuming and cumbersome for large-scale rearing. During the past 1.5 years rearing techniques reported herein have produced over 900,000 puparia. REARING PROCEDURE HOST REARING. Laboratory rearing procedures for D. saccharalis were generally similar to those described by HENSLEY & HAMMOND (1968). However, larvae were reared in 30-ml plastic cups on soybean-wheat germ diet (10-15-ml/cup) (BREWER, 1976), and eggs, larvae, pupae, and adults were held at temperatures of 26, 28, 26, and 24~ (1) In cooperation with the Delta Branch of the Mississippi Agricultural and Forestry Experiment Station, Stoneville, Mississippi 38776.

SOME EFFECTS OF SUPERPARASITISM BY LIXOPHAGA DIATRAEAE OF SUGARCANE BORER LARVAE IN THE LABORATORY

“…Mated females were placed in another cage. Fly holding procedures were described by King et al (1975). After 11 days females were randomly selected, removed from the cage, weighed, and uteri removed.…”

Sugarcane Stem Borers of the Colombian Cauca River Valley: Current Pest Status, Biology, and Control

“…Normally, evaluations of bored internodes at harvest show injury concentrated in basal internodes ; because D. saccharalis prefers new internodes near the top of the plant (White 1993), most basal injury present at harvest reflects damage sustained at earlier crop stages without further injury in later internodes. The number of instars is variable; 5-10 have been reported for larvae of D. saccharalis on sugarcane (Taylor 1944;King et al 1975;Pastrana et al 1993), whereas D. indigenella may pass through 5-11 instars to complete development on corn (Pastrana et al 1993). Total development requires 23 and 38 d in D. saccharalis and D. indigenella, respectively, at 24 °C and 67.5% RH (Pastrana et al 1993).…”

Biological control ofDiatraea saccharalis [Lep.: Pyralidae] in Florida by periodic releases ofLixophaga diatraeae [Dipt.: Tachinidae]

“…Apparently the environment was favorable for progeny survival and reproduction in Florida. Also, MILES & KING (1975) reported that D. saccharalis larvae parasitized by L. diatraeae devcloped more slowly and host pupation did not occur if larvae were parasitized before the late 5 th stage. CLAUSEN (1962) suggested that most tachinid females migrate to new areas shortly after mating if host density is low.…”