TABLE 1. Life-cycle of Heliothis virescens, studied in Barbados, W.I.

STAGE DURATION IN DAYS STAGE DURATION IN DAYS
 RangE Av. ri. Range Average
Incubation 3 3 5th instar 2 12 6
period
Ist instar 3 6 3.7 6th 5 10 8.2
2nd .5 7th 12
3rd 1 7 3.1 Pr-pupal
 period 1 4 3
4th 1 i 3.3 Pupal
 period 13 19 15.6
Total larval Larval and
period 17 30 21.8 pupal period 32 49 39.9
Complete life-cycle
(i.e. egg laying
to adult emergence) 35 52 42.9



 TABLE 2. Natural enemies of Heliothis virescens, in Barbados, W.I.


 FAMILY SPECIES STAGE ATTACKED


TABLE 3. Time (hrs.) for the development of the parasite, Bracon sp. prob. hebetor
(Say) (= Bracon brevicornis [Wesmeal]) on H. virescens larvae under laboratory con-
ditions.

DEVELOPMENT MEAN STANDARD RANGE
 STAGE (hrs.) ERROR

Incubation period 43 0.4 35.24 47.12
Larval period
(three larval instars) 48 0.9 42.00 54.00
Pre-pupal period 47 0.6 41.00 50.00
Pupal period 128 3.0 116.00 150.00
Total development period 266 5.0 267.00 1 5




 Most of the parasites obtained from overseas were released
 directly in the field, while a few species viz. Apanteles
 marginiventris (Cresson), Bracon hebetor (Say), Bracon sp. prob.
 bebetor (Say) (= Bracon brevicornis [Wesmeal]), Campoletis
 chloridae (Uchida), Campoletis flavicincta (Ashmead) and
 Eucelatoria bryani (Sabrosky) were bred in the laboratory, and
 some of these were released over a long period of time.
 1. Apanteles marginiventris (Cresson) was obtained from the
 Indian and Pakistan Stations of CIBC during 1970 and
 1975.
 It is a solitary larval parasite, attacking first and second
 instar larvae of Heliothis and Spodoptera species. The
 female inserts a single egg into the larval body, and the
 parasite develops internally. The full-grown grub emerges
 from the larval body and spins a white silken cocoon for
 pupation.
 Between 1970 and 1980, it was recovered from the larvae
 of Spodoptera eridania (Cramer) on Beta vulgaris and
 Solanum melongena.
 2. Bracon hebetor (Say), a gregarious, ecto-larval parasite was
 introduced from the Indian Station of CIBC during 1970
 and 1975, for trials against Heliothis spp. and F. cistipennis.


VOL. XX-PROCEEDINGS of the CARIBBEAN FOOD CROPS SOCIETY


 A small culture was built, and some 3,000 adults were
 released in pigeon-pea plots. The parasite was first
 recovered in 1973, when 3.0 17.5%, average 7.5% larvae
 of H. virescens were parasitised. The average percentage
 parasitism was 2.4 in 1974, 6.3 in 1975 and 9.2 in 1976.
3. Bracon sp. prob. hebetor (Say) (very close to Bracon
 brevicornis [Wesmeal]). In St. Vincent during February
 1983, the parasite attacked medium to full-grown larvae of
 H. virescens and Ancylostomia stercorea (Zell.), in pigeon-
 pea pods. Some of the field collected material was brought
 to Barbados, a culture established and its biology studied.
 The parasite mates soon after emergence. The male with
 its wings extended laterally, pursues and mounts the
 female, quickly bends the abdominal tip and inserts its
 aedeagus. During this effort it occasionally vibrates its
 wings, while the female remains quiet. The male may re-
 quire a number of attempts before it mates successfully.
 Mating lasts from one to two minutes. Both male and
 female mate several times.
 Soon after mating, the female actively searches for host
 larvae. On encountering a caterpillar, the parasite sudden-
 ly ceases movement and thrusts her abdomen with the
 oviposter extended forward between her legs. Maintaining
 this position, she gradually moves nearer to the caterpillar,
 and with a gentle sting paralyses it instantly. Thereafter,
 she may feed on the body wound at intermittent intervals
 for several hours, before laying eggs on it. The eggs are laid
 loosely on any part of the body.
 The biology of the parasite was studied in the
 laboratory. The details are given in Table 3.



 Between 21 March and 12 April, 1983, 4,500 adult para-
 sites were liberated at Fairy Valley, Christ Church. From
 April to December 1983, a further 25,870 adults were re-
 leased in other parts of the island, and work is continuing.
 The parasite was first recovered from Fairy Valley on 19
 April, 1983, when 35.2% of the larvae of H. virescens were
 parasitised. The overall parasitism ranged from 3.9% to
 44.4%.
 The initial recoveries show that the parasite may build
 up higher populations during wet weather when the pest
 population will also increase, and the green pods, a prefer-
 red site for attacking the host will also be in greater
 numbers.
4. Campoletis favicincta (Ashmead), a native of Uruguay,
 was obtained through the Commonwealth Institute of
 Biological Control, West Indian Station, Trinidad, during
 August 1981, for trials against Heliothis and Spodoptera
 species. The parasite was cultured on Spodoptera larvae,
 because of their convenient mass production in the
 laboratory.
 The parasites mate soon after emergence. The male ac-
 tively pursues the female, moving its antennae and wings
 vigorously and grasping her with its forelegs, bends the ab-
 domen anteriorly and inserts the aedeagus. Mating lasts for
 1.50 to 3.35 minutes. Both sexes mate several times.
 Mated females show reluctance to mate again, but male(s)
 pursue them to remate. Sometimes, over-mating kills the
 female.
 Usually the female requires a two to three days
 preoviposition period after mating, but if the hosts are
 available earlier, she will parasitise them. Progeny from
 these will be exclusively male.
 The parasite prefers two to four day old larvae, but
 under forced conditions, it also attacks five to six day old


caterpillars.


39


Ir- clcgramna r. f-ciatum YerK.
2Ia2on sp.
Paras erola (=Perisierola)
sp. prob. nigfriferur (Ashmead)
ArchTtc s tnarnrrtrjs (Townsend)
Arh'-ra'-; nrilii-ntris Wulp
Cclo,;eao a sa:i-irnea (L.)
Npohus sp.
SChryopa sp.
Ch_)yopa laratua Bks.
Chrysraa I imitata Nav.
Polistes barbadensis Richards


Egg-parasite
Larval parasite

Larval-pupal para.
Preys upon eggs
and young larvae
 do -
 do -
 do -
 do -
Preys upon larvae


Trichogrammatidae
Braconidae
Bethylidae
Tachinidae
 to
Coccinellidae
 11
Chrysopidae
 of
 of
Vespidae