Ask our ex­perts


NZ Gardener - - Contents - Bar­bara Smith

Your ques­tions an­swered


QWe had a great crop of chill­ies and pep­pers but some 'Wild­fire' chill­ies had patches of dis­coloured flesh and a small hole. The seeds were brown to black­ish and ob­vi­ously af­fected by some­thing. One chilli had a pink cater­pil­lar inside. What is it? JEAN DAY, NEL­SON

ABug­man Ruud Klein­paste iden­ti­fied this as the poro­poro fruit or stem borer, Leu­cin­odes cordalis, pre­vi­ously known as Sce­liodes cordalis.

This moth is na­tive to New Zealand and is found in the North Is­land and in Marlborough, Nel­son and eastern coastal areas as far south as Dunedin. It’s also found in Aus­tralia.

The host plants for the cater­pil­lars in­clude solanum rel­a­tives, egg­plants, pepino, toma­toes, pota­toes, and var­i­ous night­shade species in­clud­ing poro­poro plus datura, capsicums and chill­ies.

Adult moths are pale brown with speck­led tri­an­gu­lar wings. They are ac­tive in early sum­mer. After mat­ing the fe­males lay eggs on de­vel­op­ing fruit or on the un­der­side of leaves. When the eggs hatch, the cater­pil­lars chew a hole through the skin of a fruit or the midrib of a leaf. Young cater­pil­lars bur­row un­der the skin, but older ones bur­row into the fruit to feed on the de­vel­op­ing seeds.

After moult­ing five to six times the fully-grown cater­pil­lar turns red be­fore leav­ing the fruit. It is thought that the colour makes the cater­pil­lar harder for preda­tors to see as it only comes out at night.

The cater­pil­lar spins a co­coon cov­ered with de­bris for cam­ou­flage and pu­pates for a week to 10 days. There are one or two gen­er­a­tions a year. Cater­pil­lars form­ing co­coons in Fe­bru­ary re­main there un­til warmer weather in spring.

All stages of the life­cy­cle are pre­dated by var­i­ous birds, in­sects, spi­ders, par­a­sitic moths or fungi. Don’t bother spray­ing – flick off the red eggs if you spot them and en­cour­age di­verse pop­u­la­tions of ben­e­fi­cial in­sects and birds in your gar­den.


QSome slimy lit­tle green bugs that I have never seen be­fore are in­fest­ing a com­mon old bud­dleia in my gar­den and the in­fes­ta­tion seems to be lim­ited to just that tree. I want to get rid of that tree any­way but would like to get of the slimy crit­ters first. CHRIS­TINE GOBLE, MIDHIRST

AIt’s the bi­o­log­i­cal con­trol wee­vil Cleo­pus japon­i­cus which was in­tro­duced into New Zealand in 2006 to con­trol the spread of Bud­dleja

da­vidii. Spread by fine, wind­blown seed, bud­dleia is a ma­jor weed that grows any­where, even in poor soils. Thick­ets es­tab­lish quickly, pre­vent­ing growth of other plants. The dam­age done to na­tive bush and forestry plan­ta­tions out­weighs its use­ful­ness as a nec­tar source for but­ter­flies.

Cleo­pus lar­vae and adults eat bud­dleia leaves, and can de­fo­li­ate plants and even­tu­ally kill them. Bar­bara Smith


QCould you please iden­tify this strange nest found on branches of eu­ca­lyp­tus we planted on our life­style prop­erty some 20 years ago? We are in North Can­ter­bury and have not come across any­thing like this be­fore. SYLVIA ROSIE, EYREWELL

AThis sturdy co­coon is shel­ter­ing the pupa of an em­peror gum moth. An adult moth may cut its way the fol­low­ing spring but can stay inside from two to five years wait­ing for op­ti­mal weather con­di­tions.

Adult moths mea­sure 120-150mm, but only live for a cou­ple of weeks when they mate, lay eggs and die. The cater­pil­lars are bright green with a yel­low stripe down the side. They are large and ro­bust, so they are good ones for chil­dren to care for and ob­serve. My young sons were fas­ci­nated by their prodi­gious pro­duc­tion of poo! Bar­bara Smith


QThe leaves of my ‘Cin­na­mon Cindy’ camel­lias have browny/ black splotchy marks that don’t rub off. They don’t get much sun and are about 10 years old, but have flow­ered pro­lif­i­cally and been re­ally healthy un­til the last six months or so. ALICE SPENCE, AUCK­LAND

AIt is not easy to iden­tify the prob­lem with­out un­der­stand­ing the site, soil and cli­matic con­di­tions but it ap­pears to be a min­eral de­fi­ciency.

Pur­pling of the older leaves in­di­cates phos­phate de­fi­ciency and the new leaves show symp­toms of ni­tro­gen de­fi­ciency which in­di­cates they are un­der­fed. This may be caused by re­stricted root growth, de­pleted soil nu­tri­ents, in­suf­fi­cient wa­ter or too much wa­ter.

Fer­til­is­ing with an acid fer­tiliser well-wa­tered into the soil could help the al­le­vi­ate the con­di­tion. Hamish Cheetham, NZ Camel­lia So­ci­ety

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