Coreid Bugs (Coreidae)
 Two specimens of Anasa scorbutica F. were recorded. This
 species has been reported as an occasional pest of melons in Puer-
 to Rico (Wolcott, 1948).

 Asparagus Beans
 Damping-off (R. solani suspected) killed 5% of the seedlings.
 Nearly 50% of the deaths occurred during the first four days after
 emergence; the disease ceased 19 days after emergence. Powdery
 mildew (Erysiphe sp.) occurred on the basal third of ca. 75% of
 the plants 45 days after emergence. It was visible on most leaves
 by the last harvest date (70 days after emergence) and ca. 50% of
 the leaves had fallen by this time. It was difficult to determine if
 fungicide applications would have been cost-effective because
 leaf-drop from water stress and early senescence are complicating
 factors. Asparagus beans are reported to be disease-susceptible
 although less so than common beans (Martin and Ruberte, 1980).

 Aphids (Aphididae)
 The cowpea aphid, Aphis craccivora Koch, first appeared four
 days after seedling emergence and reached a peak population of
 155 individuals per plant sample approximately one week prior to
 the first harvest (Table 1). One week later the population had
 decreased by over 90% to 8.5 aphids per sample, followed by a
 slight increase during the remainder of the harvest period.
 Aphids were concentrated on the main and lateral stems, the
 underside of the leaves near the petiole and, toward the end of
 the harvest period, on the basal half of nearly-mature pods.
 Aphid damage varied depending on the age of the bean plant
 and the aphid population. Ten days after seedling emergence
 when the second pair of trifoliate leaves were expanding, high
 populations of 50-150 aphids on the entire plant were recorded
 on some seedlings. These plants became stunted and did not
 resume growth until the aphid population was nearly eradicated
 by predators six weeks later. The plants then grew rapidly and
 produced a crop; although the plant size was only about 75%
 and the yield less than 50% of the average plant.
 Bean plants that developed moderate to high aphid popula-
tions (6-20 aphids per plant sample; plant height was 80-110 cm)
four weeks after emergence were able to tolerate aphid damage
reasonably well for an additional three weeks. Some leaf curling
and growth reduction occurred, but few pods had aphids on
them. After this time, predators greatly reduced the aphid
population on ca. 75% of the plants with high populations.
Parasitized aphids and parasitic wasps were also observed but not
collected. Plants that still had high aphid populations at harvest
also had aphids on the basal half of the pods that were ready for
picking. The pods were slightly curled and generally unacceptable
because of the crushed aphids left on the pod during picking.
 Plants with low aphid populations four weeks after emergence
(1-5 individuals per plant sample) grew well and the size and crop
yield were satisfactory (approximately 4400 kg/ha or 4000
lb/acre). The pods were generally aphid-free.


Aphid Predators
 P. clavatus larvae (Syrphidae) appeared ten days after plant
 emergence and reached a peak population of 38 larvae per plant
 sample five weeks later (one week prior to harvest) (Table 1). The
 maximum populations of syrphid larvae and aphids were record-
 ed on the same sampling date although the aphids had nearly
 reached this peak the previous week, whereas syrphid larvae were
 less than half their maximum population at that time. One week
 later (at harvest) the syrphid population had decreased by 85%
 and the aphids by over 90%. No syrphids were recorded during
 the remaining two weeks on plant samples although they were
 observed on other bean plants in the rows.


 Chrysopa sp. larvae (Chrysopidae) with a white, waxy covering
 were first recorded 24 days after seedling emergence. The popula-
 tion increased to 25 larvae per plant sample two weeks later and
 peaked at 65 larvae per plant sample the following week which
 was the same date as the maximum aphid population (one week
 before harvest) (Table 1). By the next week the lacewing popula-
 tion had declined 81% ,along with an even greater reduction in
 the aphid population. Adult lacewings were not commonly
 observed.
 C. sanguinea adults (Coccinellidae) were first recorded 24 days
 after seedling emergence. They reached a maximum number of
 nine per plant sample three weeks later when/the aphid popula-
 tion peaked, and rapidly decreased thereafter (Table 1). Unlike
 lacewing adults, lady beetle adults were much in evidence. Larvae
 were not recorded until nearly seven weeks after seedling
 emergence and their population peaked two weeks later, during
 the middle of harvest, at seven larvae per plant sample. Lady bee-
 tle larvae continued the predation pressure as the impact of the
 syrphid and lacewing larvae declined during the last three weeks
 of harvest.

 Ants (Formicidae)
 S. geminata were tending cowpea aphids and the ant popula-
tions increased parallel to the aphid populations. The ant
number peaked at 6.3 individuals per plant sample during the
same two weeks of maximum aphid populations (Table 2) and
declined rapidly thereafter. Small ant nests were common at the
base of bean seedlings with the highest aphid and ant numbers,
but gradually declined as the plants matured so that few nests
were still present by the time harvest occurred. Ants did not cause
any direct damage to bean plants although nests at the base of
seedlings may have increased soil dessication.





TABLE 1. Population development of aphids and aphid predators on asparagus
beans.

 Mean No. Specimens per Plant Samplea
 Aphis Pseudodoros Chrysopa Cycloneda sanguine
 craccivora clavatus sp. adults larvae
 Date larvae larvae
 1/28b 2.5
 2/4 4.6 1
 2/11 23.3 2
 2/18 40.6 12 1 2
 2/25 43.8 13 2 2
 3/5 151.3 16 25 4
 3/11 155.2 38 65 9 1
 3/19c 8.5 5 12 0 6
 3/25 18.3 4 1 7
 4/11 16.4 7 6

 aA plant sample consisted of 1 trifoliate (including petiole) near the
 bottom, middle and top of plant, and the length of the main stem. The
 first true leaf substituted for a trifoliate on newly emerged plants.
 N=96 for weeks 1-4 and n=24 thereafter.
 bSeedlingsemerged Jan. 24-25, 1982.
 CFirst harvest was March 22, 1982.


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