Crab Spiders

 Each fall local gardens are invaded by crab spiders, also known as spiny-backed spiders.  There are two species of crab spiders on the Big Island of Hawaii, both are shaped like tiny crabs approximately ½ inch across. One is white with black spots and 6 red spines. The more common one also has spines, although shorter, with two distinct white spots on its speckled yellow-brown back. In certain locations, crab spider populations increase in the fall and decline in the late spring.

These spiders are different from other spiders in their web building techniques. Their webs are interconnected, building condominiums right outside your door, under the eaves, between the shrubs and in the trees.  They seem to be spun everywhere, but the spiders are not a nuisance indoors. 

People, especially farm workers, have been bitten when the spiders fall on them or are trapped within their clothing. Females lay eggs away from their webs, on the leaves of trees and elsewhere. The egg masses look like a flat patch of fluorescent green cotton candy which turns yellow when the eggs hatch. Disposing of this egg mass will, of course, help to reduce the spider population.

Spiders, including the crab spiders, are some of the best bio-control agents known, because they feed on large quantities of insects such as aphids, ants, thrips and termites. They should be tolerated as much as possible. But, people do have their limits. A soap and/or oil solution will kill them. In addition, many household, aerosol insecticides will do a good job of killing the spiders. Before using, read the label for precautions and application sites. Note: application to plants may cause severe burning.

Banana Basics

The banana plant is actually a perennial herb. The fruit is harvested 11-15 months after planting. Individual bananas turn light green to yellow and angular corners become rounded.

Bananas require a well-drained soil, with a pH range of 5.5 - 6.5. They also need rainfall of 100 inches or more, well distributed throughout the year along with full sun, wind protection and an average temperature of 81degrees Fahrenheit.  

In general, banana plants need a fertilizer with high amounts of potassium (K), along with nitrogen (N) and phosphorus (P). Around the Hawaiian Islands, soils vary, some being richer than others. The University of Hawai`i recommends applying 2 lbs. of a fertilizer similar to 10-5-20 (N-P-K) three times a year . This amount is applied per mat. When referring to bananas, a group of plants is known as a mat. A properly maintained mat will have one plant in fruit, one plant half-grown and one plant just emerging from the soil. Applying compost to the surface of the banana mat is beneficial, but most likely will not supply enough nutrients, especially nitrogen, for optimum growth. 

Green bananas can be stored up to seven days at room temperature or up to 20 days under refrigeration. Neither green nor ripe bananas, however, should be stored at temperatures lower than 58 degrees Fahrenheit.  Cooler temperatures will cause surface damage. 

Orange Trees with Vigorous Shoots

My neighbor recently asked this question:
"I have an older orange tree in my front yard. One of the branches is very vigorous, has large thorns on it, and the fruit is very sour.  Why is this branch different from the rest of the tree?" 

This is a fairly common problem in oranges and other sweet citrus fruit. The vigorous shoot, or branch, originates from the rootstock, that is, below the original graft or budunion. This branch, therefore, is not genetically part of the grafted orange variety. 

Rootstocks are chosen because they possess resistance to disease or some other cultural quality desired by the grower. The fruit borne from the rootstock, although a citrus species, is often sour, bitter and with little juice. Occasionally a bud will break from the rootstock, develop into a branch and grow up through the tree. Eventually this branch can set fruit, but as noted, usually of inferior quality. These sprouts or branches should be cut out. Since they are usually more vigorous than the grafted portion of the tree, they could eventually dominate the entire tree if not removed.